SRAM Guide Brakes

First Ride: SRAM Guide Brakes

New hydraulic disc systems for mountain bikes launch SRAM to the head of the braking field

ron koch

(Photo by SRAM’s new Guide brakes are top-notch performers. (Courtesy))

Lets not beat around the bush—ever since SRAM’s Avid brand launched its Taperbore technology in 2008, its hydraulic disc brakes have struggled with reliability issues. So, not surprisingly, SRAM branded the new trail-focused brake under its own banner and starts fresh with a refined version of the tried-and-true piston-port design. After three days of hard riding in the Moab, Utah desert I can say the SRAM Guide brake seems like a smashing success with performance that rivals—or even beats—the best on the market. If their long-term durability matches their initial performance, Guide brakes will likely restore the brand’s reputation as a maker of lust-worthy mountain bike stoppers.

SRAM’s design goals when starting the Guide project two years ago were for it to be robust, consistent, and relatively light. “Guide is not going to let you down,” says James Alberts, mountain bike brake product manager. SRAM built a more forgiving system that performs more consistently, even with a less-than-perfect bleed or a little air in the reservoir. Guide’s lever and master cylinder is where the magic really happens—other than a few minor hardware changes, the four-piston caliper is essentially the same as the current X0 Trail brake.

Like all other brakes on the market and Avid’s old Juicy models, the Guide uses a cup seal and timing port design in its master cylinder. There is one clever difference though—the timing ports protrude into the reservoir, putting their orifices in the middle of the space so air bubbles are far less likely to enter the system—even if the bike is inverted or hung up. This is something I’ve never seen an any brake before. The forged body is anodized and compared to Avid’s brakes, the Guides maintain more precise tolerances between the seal and bore for durability and a smooth feel at the lever. There is three times more negative volume (the area behind the bladder without fluid) than before and almost double the positive volume (the area inside the reservoir with fluid). The bladder is now Butyl instead of EPDM rubber, which SRAM says better prevents air and moisture migration while remaining extremely flexible. It still uses DOT 5.1 fluid. Guide brakes also use the same existing bleed kit and process as Avid models.

Inside the lever is a linkage and roller system dubbed SwingLink that reduces lever travel before engagement—something SRAM calls deadband and is also referred to as free stroke. The curved profile of the SwingLink’s cam engages a roller that pushes the piston to reduce deadband. SRAM engineers worked hard to make the curve progressive right up until the pads contact the rotor—then it’s linear to let the rider better control the braking power. Pad contact point, or lever free stroke, is still adjustable to add or reduce deadband and changes independently of the tool-free reach adjustment. While adjusting the pad contact point dial, SRAM says the cam automatically compensates to minimize change in leverage curve. To fight wear, the cam piece is forged and machined steel while its pivots ride on teflon bushings and rollers. SRAM tested the assembly successfully past one million cycles. To put this into perspective, data acquisition equipment revealed that an hour-long loop on SRAM’s local Colorado Springs trails netted an average of 180 brake applications (cycles).

Matched to the brakes are all new SRAM Centerline rotors: They’re 5 grams heavier than the current SH1 in a 180mm diameter but keep the center of friction more consistent to minimize vibration and improve temperature management. There are now 12 instead of 6 spokes for better heat management and warping control. Centerline is available in 140, 160, 170, 180, and 200mm diameters.

There will be three versions of Guide. The top offering is the RSC (Reach, SwingLink Contact point adjust), which costs $199. It has a ball bearing in its main lever pivot and comes with sintered metallic pads. The RS ($149) and R ($129) models have bushings in their lever pivots and come with organic pads. The R does not have Swinglink but a standard direct link instead. Guide RSC weighs in at 375 grams with a 160mm rotor, 800mm-long hose, and all mounting hardware. That’s 10 grams more than the current trail brake. At this point there is not a model with a carbon lever blade but SRAM is working on one. Guide models will start appearing in shops this July. Avid is not disappearing—yet. There will still be mechanical DB1 and DB3 mechanical brakes as well as the gravity-oriented Code hydraulic brake still under the Avid name.

Ride Impressions I rode the Guide RSC brakes with metallic pads over three days—twice on a Giant Trance Advanced and once on a Specialized S-Works Camber. While setting them up I noticed that the lever feels shorter and has lighter action than before—not as short or light-feeling as Shimano but close and a big improvement over most previous Avid models. An hour or so into the first ride on Moab’s Captain Ahab trail, SRAM's brake product manager, James Alberts, rolled up and asked how I liked the brakes. I had to think about it for a few moments before saying "I don't know. I didn't even notice them." With a big smile he said, "That's the idea." The power was there when I needed it and in the exact amounts my finger asked for.

Confession time: My favorite brake over the last few years has been the Shimano XTR and specifically its BR-985 race brake upgraded with metal radiator pads. These 985s offer a nice linear progression and are easier to control at lockup. I've noticed these levers paired to a variety of calipers on sponsored athletes too, so great minds must think alike.

The Guide's power at pad contact is linear, easy to modulate and very similar in feel to my favorite Shimano brake but with perhaps even less free play and more adjustability. This is a compliment of the highest order. I run my levers close to the bars and with as little free stroke as possible. I ran the free stroke all the way out with the reach dialed in for the same pad contact point in relationship to the grip for a while to see how the cam system feels at the other extreme. It was indeed similar but had more progression—the SwingLink system compensates some, but not completely, for contact point adjustments. The SRAM Guide’s SwingLink allows more progressive leverage from the levers. (Courtesy)
Over the next few days the brakes continued to impress with a rock-solid consistency in feel and power. The pad contact point at the lever was always in the same place and the levers were even. The Guide brakes ran silently too. We didn't ride in the wet and in all fairness none of the descents—not even the Porcupine Rim—posed a huge demand on the brakes. Longer, more consistent braking on steeper trails back home in a variety of weather conditions will reveal the final verdict. And more time will show the brakes’ true long-term reliability. If they pass both tests, the Guide brakes will be a real winner for SRAM and be a force to be reckoned with.